1). Field of the Invention
The present invention relates to devices and methods for occluding a fallopian tube to cause sterilization.
2). Discussion of Related Art
It is often desired or necessary for medical reasons to permanently close the fallopian tubes of women. The procedures currently proposed for occluding the fallopian tubes to effect sterilization include occlusion by insertion of a foreign body.
Fallopian tube occlusion by a foreign object presents many issues in creating an effectual design. The most important issue is preventing expulsion of the device by the fallopian tube. Fallopian tubes are functionally complex, and they have the ability to move objects through peristaltic (muscular contraction) and ciliated forces, and the direction of the force varies with menstrual cycle. In a recent study, a fallopian tube implant designed by American Medical Systems Holdings Inc. had an unacceptable number of expulsions. The device is believed to be overly rigid and thus had difficulty in placement and was ultimately ejected by the fallopian tube at a higher than acceptable rate. In order to achieve hysteroscopic tubal occlusion success, consistent delivery, acceptable placement location, and implant retention is critical. Such implants require a balance of flexibility, compressibility and rigidity. Flexibility is required to track the delivery system to the proper location, rigidity is required to either push the implant out of a delivery catheter or retract the delivery catheter while holding the implant in place and compressibility is required to retain the implant in the fallopian tube. Too much rigidity may be detrimental to long term success of the implant allowing the natural forces in the fallopian tube to either move the device into the peritoneal cavity or into the uterus.